Inverters provide 120 VAC power, the same as what comes out of your home wall outlets.
The onboard generator also provides 120 VAC power, the same as what comes out of your home wall outlets.
Obviously shore power also does the same.
An inverter only supplies power when you're running solely off of the house batteries. That can be while parked or while driving.
If you have a residential refrigerator it may have its own inverter to run the fridge or not. It differs from RV manufacturer to manufacturer.
The only time you need the inverter to do its thing is when you're not on shore power and not on generator. So if you're driving down the road and do not have the generator running you may need the inverter. It all depends on what you're trying to use. In most cases, I would expect you do not need the inverter.
2020 Georgetown GT5 34H5